How the Bruins win: When the Bruins play 60 minutes of disciplined, puck-control hockey, they are almost unbeatable. The key to much of their success is they’re the best faceoff team in the league, so they start with the puck. And because they have such big bodies with skill, they usually do a good job of hanging onto it.

How the Maple Leafs win: By rolling four lines that contribute and being a difficult opponent on most nights. Through mid-April, the Maple Leafs were leading the league in hits, blocked shots and fights. The penalty kill that has been the bane of their existence the past couple years was top-three in the league and their goaltending has improved significantly.

How the Bruins lose: Lapses in concentration and a strange inability to start games well often leave the Bruins fighting to get back into them. They have a more balanced attack than when they won the Cup two years ago, but their top players tend to go through long slumps. We’re talking about you, Milan Lucic.

How the Maple Leafs lose: When they lose their composure and discipline in terms of taking penalties and straying from their system. They go through long stretches where they get behind in games and have difficulty managing the puck in their own end. Late in the season, the Leafs led the league in giveaways by an enormous margin. Many of those are from their defensemen.

Bruins goaltending: Coach Claude Julien has never believed in overworking his No. 1 goalie during the regular season and that will benefit Tuukka Rask, who will taste his first real playoff experience in three years. The Bruins have supreme confidence in Rask’s clutch ability.

Maple Leafs goaltending: The Leafs were 27th in shots against. For the first time since Ed Belfour, they have goaltending good enough to push them into the playoffs.

Bruins question mark: The Bruins had the worst power play of any Stanley Cup winner when they captured the championship in 2011. Their play with the extra man is even worse this season. How can a team that can’t score on the power play go deep in the playoffs?

Maple Leafs question mark: How will the Leafs respond in the playoffs when fighting is virtually non-existent? They led the league in major penalties and were second in PIM, but will they be that tough when Colton Orr and Frazer McLaren spend much of the game on the bench?

Winner and why: The Maple Leafs won just one of four games against the Bruins this season and Boston has owned Toronto in the past few years. That said, the Leafs have narrowed the competitive gap of late and are a more physical team than the Bruins were accustomed to. Boston also is having a tough time producing offense and this will be Tuukka Rask’s first big playoff run as the Bruins’ clear-cut No. 1 netminder. Is an upset possible? The way Boston stumbled into the post-season (winning two of their final nine regular-season games), absolutely. Is it probable? We wouldn’t go that far. Toronto will have to prove they can play with the Bruins for extended stretches before anyone will expect them to. Bruins in 6.